Evolution of the Rate of Live and Tapped Trees of Hevea brasiliensis Clones, Muell. Arg. the First 15 Years of Plantation Establishment

The density of tapped rubber trees in a plantation is a determining parameter of its productivity. It is related to the number of trees planted per hectare, the evolution of which can be influenced by several factors that act on the trees from the year of establishment to the time of tapping. To this end, a study to determine the evolution of the rate of live trees and tapped trees of eight rubber clones during the first fifteen years of establishment was carried out in southwestern Côte d'Ivoire. At opening, rubber trees planted at 510 trees/ha (7 m x 2.80 m) were bled in a descending half-spiral at different tapping and stimulation frequencies. The experimental design was a Fisher block design with 6 treatments (d2, d3/4y, d4/4y, d4/8y, d5/8y, d6/10y) and 3 replications. The results revealed that the rate of live trees and tapped trees was not influenced by either clone or latex harvesting treatment. The rate of live trees decreased progressively from the immature phase of the plantation (94.71 ± 1.34%) to the end of the downward tapping (91.55 ± 0.67%). The rate of tapped trees increases from the time of planting (69.51 ± 8.03%), over the years (92.00 ± 1.39%) until it equals the rate of live trees (92.00 ± 1.08%) before gradually decreasing to 88 ± 3.78%. It should be noted that the factors influencing the evolution of the rates of live and taped trees caused less damage to the rubber trees. And this influence is not dependent on clone, metabolic activity class and latex harvesting system.

Hibiscus elatus (blue mahoe).

The Caribbean tree H. elatus, known as blue mahoe or majagua, is a highly valued, fast-growing timber species that has adapted to a wide range of sites and is often used in reforestation. It produces excellent timber for high-grade furniture, but can also be used as a windbreak. Ease of germination results in successful plantation establishment. It could be grown on a larger scale as a plantation crop but suffers from epicormic branching and sweep. H. elatus is also grown for ornamental and shade purposes and is the national tree of Jamaica.

Local was best: sourcing tree seed for future climates

As climate change accelerates, foresters are looking to ever warmer climates to secure sources of climatically adapted tree seed with which to establish healthy and productive plantations. However, as seed procurement areas approach jurisdictional boundaries (states, provinces, nations), across which seed and seed transfer systems are not typically shared, innovative approaches are required to identify those plantation areas for which suitable domestic provenances will be lacking, and areas in neighbouring jurisdictions with matching warmer, future climates that could fill domestic seed supply gaps. We describe a straightforward, climate envelope approach to locate these areas, using British Columbia (BC), Canada, and the Pacific Northwest (PNW) USA to illustrate the analysis. We find that 21% of BC’s ecosystems (seed zones) will be at moderate or high risk of lacking adapted domestic provenances for plantation establishment by 2040. Importantly, however, we find large areas in the PNW that should be able to fill most of BC’s domestic seed supply gaps. Spatial analyses of this type will inform seed suppliers, managers and policymakers where alternative seed procurement arrangements are needed and underscore the operational and policy barriers to acquiring seed from warmer jurisdictions. More broadly they also highlight the need for inter-jurisdictional cooperation in matters pertaining to resource management.

Economic evaluation of growing new blackberry (Rubus caesius L.) cultivars under the conditions of the Western Lisosteppe of Ukraine

The authors present the results of evaluating the economic efficiency of growing blackberry cultivars of different ripening terms in the plantation of the Institute of Horticulture of the National Academy of Agrarian Sciences (NAAS) of Ukraine. The capital investments on the creation and management of 1 ha of the plantation were 517.3 thousand ₴ (under the planting plan 1.25 х 3.00 m), the trellis putting and laying being about 50 % of the mentioned sum. The productional costs on the fruit-bearing plantation management depended on the cv yield, expenditures for salaries and wages, fertilizing, protective means, fuel and lubricant use, plants covering for winter, the agricultural technics amortization etc. and were within 144.1-283.0 thousand ₴. The wholesale price of the early ripening varieties products was 80.0 ₴/kg. Thus the receipts of the realized products were within considerable limits. Cvs Thornfree, Asterina, Čačanska Bestrna and Chester were characterized with the lowest cost per 1 t of the products (22.61; 23.10; 23.43 and 24.97 thousand ₴ respectively while Nasoloda and Karaka Black with the highest one (38.98 and 37.85 thousand ₴ respectively). The profit per 1 ha of inland variety Nasoloda plantations was the lowest one among the presented cultivars, (42.74 thousand ₴) whereas the early ripening cvs Loch Tay and Brzezina ensured 380.79 and 335.18 thousand ₴ respectively. The same cvs distinguis hed themselves for the highest profitableness level (185.2 and 172.4 % respectively as well as for the shortest rates of the capital investments return recovery – 3.4 and 3.5 years respectively. The profitableness of cv Karaka Black was 111.3 % with the rate of return cost recovery 5.0 years because of the lower yield. This was economically favourable too though. The average and late ripening cultivars which formed the yield of 7.0-8.0 t/ha had the rate of the investment return 4.0-5.0 years. It should be noted that it was cv Thornfree that distinguishhed itself for the highest profitableness (121.1 %) among late ripening cvs with the rates of capital investments on the plantation establishment return 3.4 years.

Evaluation of Indigenous Knowledge and Fuel Value Index of Some Selected Sudano-Sahelian Fuelwood Species in Damaturu, Yobe State of Nigeria

Fuelwood utilization in the sudano- sahelian region requires massive felling of tree species which in turn resulted to deforestation and sand dunce couple with scarce vegetation in the region. Moreover, fuelwood is not only used for domestic and commercial purposes but for livelihood sustenance. This increases the demand and intensity for fuelwood through indiscriminate felling of trees species for energy use, with a trend that does not appear to have the possibility of meeting the increasing demand in the future. The study aimed to evaluate the indigenous knowledge and fuel value index (FVI) of ten selected sudano-sahelian fuelwood species and the results revealed a significant relationship between the indigenous knowledge and Fuel value index (FVI) of the ten selected fuelwood species. Higher FVI of 13.56MJ/m3 % 2 was obtained in A. leiocarpus followed by 6.61 MJ/m3 % 2 and 6.53MJ/m3 % 2 obtained in B. aegyptiaca and C. arereh meanwhile, lower energy fuelwood ranged from 0.11MJ/m3% 2 obtained in C. lamprocarpum. to 0 85MJ/m3% 2, in S. birrea respectively. Meanwhile, A. leiocarpus, C. arereh, C. molle, and B. aegyptiaca were the most preferred and possessed good fuel quality. The indigenous knowledge might not be solely based on their fuel properties but availability and other possible reasons. Therefore, those fuelwood species identified with higher energy value can be incorporated in to fuelwood plantation establishment programs and those with lower energy value fuelwood should be allowed for environmental restoration and amelioration.

Predilection of Chaitophorus populeti and Phyllobius oblongus on four clones of white poplar

The predilection of Poplar shoot aphid (Chaitophorus populeti Panzer) and European Snout Beetle (Phyllobius oblongus L.) in the first and second growing season in two experimental plantations. Four white poplar clones were tested: Villafranca, L-100, L-80, and L-12. The first experimental plot was established at the beginning of 2019 and the second in 2020 near Novi Sad (northern Serbia). Predilection of C. populeti Panzer was performed on three plants per each of three blocks and every of four clones. Predilection of P. oblongus L. was evaluated on all leaves of five shoots on three plants per each of three blocks of every of four clones. According to the results of analysis of variance and Tukey's test for several traits describing intensity of damage and percentage of damaged leaves, there was significant difference between examined clones in prevalence of P. oblongus L. Significantly stronger attack was found for clones L-80 and L-12 than on Villafranca and L-100 in both years on plants in their first growing period. The damage from this pest in second growing period could almost not to be detected. In case of C. populeti Panzer, the prevalence was assessed according to the percentage of colonized shoots. The differences between examined clones were significant only in first growing period in 2019, where the strongest attack was found on clones Villafranca and L-100, and the weakest on clones L-80 and L-12. Results of the study are particularly important in the context of clones L-12 and L-80 performances evaluation, considering that these clones are still in the experimental phase of testing. Likewise, the intensity of attacks of studied pest species suggests that special attention to their presence and spreading should be paid in the first growing season after plantation establishment.